follows Rose Hale, a call center employee trapped overnight with her coworkers when a power outage turns deadly and a mysterious killer begins hunting them one by one. As fear escalates, Rose uncovers chilling clues that the attacks are deeply personal and tied to a shared secret among them. The truth spirals into a psychological confrontation, revealing the killer may be a manifestation of Rose's own fractured mind—and escaping means confronting the darkness within herself.